This invention relates to a method of applying an aqueous ammoniacal ionic solution of metal alkanoates to seeds to stimulate early seedling growth. More particularly, this invention relates to a method of pretreating seeds with an aqueous ammoniacal ionic solution of metal alkanoates and of applying such solutions to seeds, in-furrow, at planting.
Traditionally, substantially anhydrous liquid ammonia has been injected below the soil surface, under pressure, for use by growing plants as a source of nitrogen. Anhydrous liquid ammonia is typically applied in fallxe2x80x94after the end of the growing season, in early springxe2x80x94prior to planting, or in late springxe2x80x94post-emergence, i.e. after a crop has germinated and leafed out. While anhydrous liquid ammonia is readily assimilated by plants and thus is a preferred fertilizer, the pressurized injection methods conventionally used are not suitable for use under wet soil conditions. When weather conditions are unsuitable, growers may skip scheduled early spring, late spring or fall applications of anhydrous liquid ammonia. When this occurs, crop yields are likely to be reduced unless alternate forms of nitrogen application are used.
Plant activants and other fertilizers and materials are sometimes combined with anhydrous ammonia to form augmented solutions for application to the soil with the anhydrous ammonia to further enhance plant growth and increase crop yields. U.S. Pat. No. 3,909,229 for xe2x80x9cPlant Nutrientsxe2x80x9d to Ott, incorporated herein by reference, teaches aqueous ammoniacal ionic solutions of zinc carboxylates, for example zinc acetate in combination with ammonia, as effective fertilizers. U.S. Pat. No. 3,997,319 for xe2x80x9cFertilizing Methodxe2x80x9d to Ott, incorporated herein by reference, teaches the application to soil below the surface of the soil, a substantially anhydrous liquid ammonia containing an ionic solution of a zinc carboxylate. This method supplies both zinc and nitrogen to plants growing in the soil. Zinc acetate is disclosed in this patent as a suitable zinc carboxylate. U.S. Pat. No. 4,352,688 for xe2x80x9cNitrogen Fertilizersxe2x80x9d to Ott, also incorporated herein by reference, teaches that low molecular weight alkanoic acids and alkanoate anions, particularly acetic acid and acetate ions, effectively promote plant growth and yield by enhancing the ability of nitrogen fertilizers.
As disclosed in the above-identified patents, alkanoic acids and alkanoate anions, for example metal ammonium alkanoates and zinc ammonium acetate, are applied in conjunction with anhydrous ammonia, often by injection under pressure. When employing this application technique, application of the alkanoic acid and/or alkanoate anion depends upon successful application of the anhydrous ammonia. If weather conditions are unsuitable for application of the anhydrous ammonia, crops growing in or to be planted in the soil to which the anhydrous ammonia was to be applied may forego both needed nitrogen and plant growth stimulation afforded by the alkanoic acid or alkanoate.
When a scheduled application of an anhydrous ammonia/alkanoic acid or alkanoate combination is missed, a dried or liquid fertilizer containing the alkanoic acid or alkanoate is sometimes applied as a pre-emergence or side dressing. However, the effectiveness of side dressing techniques on growing plants is typically not as great as when a fertilizer is applied closer to the plant roots.
One agricultural crop additive of the class of aqueous ammoniacal ionic solutions of metal alkanoates described above is commercially available under the ACA(copyright) Concentrate 15-0-0 trademark from Platte Chemical Company of Fremont, Nebraska. ACA(copyright) Concentrate 15-0-0 is an aqueous ammoniacal ionic solution of zinc acetate. ACA(copyright) us currently available as a liquid containing approximately 15% by weight ammoniacal nitrogen and approximately 17% by weight zinc (hereinafter xe2x80x9cACA(copyright)xe2x80x9d). ACA(copyright) is typically applied at a rate of from ⅓ to ⅔ pint per acre, preferably xc2xd pint to ⅔ pint per acre. Application of alkanoates at these low rates is generally understood to require application of the alkanoate in conjunction with a liquid carrier, such as anhydrous ammonia or a nitrogen fertilizer solution. This requirement derives from the relatively high viscosity of aqueous ionic solutions of metal alkanoates such as ACA(copyright) and the inability of planting equipment to deliver such fluids at the desired lower flow rates.
Because of the concentrated character of many nitrogen fertilizers, including pressured anhydrous ammonia, care is taken to avoid applying these fertilizers directly to the roots of growing plants or in contact with newly planted seeds. Instead, these fertilizers are conventionally applied a distance from the plant roots. For example, ACA(copyright), when mixed with liquid or dry granular fertilizer and applied as a starter simultaneously with the planting of corn seeds, is typically applied 2xe2x80x3 or more to the side of a furrow in which the seeds are placed and 2xe2x80x3 or more below the level of the seeds in the furrow. By distancing the fertilizer/alkanoate mixture from the corn seeds, the seeds are not burned by the fertilizer and the sprouted plants eventually can access to the fertilizer/alkanoate mixture after the plants are established.
Thus, application of ACA(copyright) and other aqueous ammoniacal ionic solutions of metal alkanoates near plant roots has traditionally been limited by restrictions on placement of the carrier ammonia or other fertilizer liquids or solids. Despite this, and although the precise mechanism by which the aqueous ammoniacal ionic solution of metal alkanoates enhance plant growth is not completely understood, it appears that application of such solutions is especially important at early leafing stages of development of crops such as corn, soy beans and wheat.
It is against this background that the significant improvements and advancements of the present invention have taken place.
It is the principal object of the present invention to apply an aqueous ammoniacal ionic solution of metal alkanoates to seeds to stimulate seedling and later plant growth and to increase crop yields, without injury to seeds or plants.
It is a further object of the present invention to accomplish the aforementioned object without requiring the aqueous ammoniacal ionic solution of metal alkanoates be applied to the soil in a carrier medium such as anhydrous ammonia, liquid fertilizer, dry granular fertilizer or other medium.
It is a yet further object of the present invention to accomplish the aforementioned objects as early as possible in the development cycle of plants without risk of omitting an application of the aqueous ammoniacal ionic solution of metal alkanoates because of inclement weather.
In accordance with the major aspects of the present invention, an effective amount of an aqueous ionic ammoniacal ionic solution of metal alkanoates is applied directly to uncovered seeds, in-furrow, at planting. Following placement of the seeds in a furrow, typically in an automated fashion by a seed planting machine, the solution is automatically and continuously dispensed onto the uncovered seeds in-furrow and to the surface of the soil of the furrow, directly adjacent the seeds.
In an alternate embodiment of the present invention, seeds are treated before planting with an effective amount of an aqueous ammoniacal ionic solution of metal alkanoates.
Preferred alkanoates applied pursuant to the method of the present invention contain from two to six carbon atoms, with acetate ions most preferred. Preferred metal alkanoates contain agriculturally acceptable metals selected from the group consisting of boron, calcium, copper, iron, magnesium, manganese, molybdenum, potassium, sodium and zinc, with zinc particularly preferred. The most preferred solution with which the present invention may be practiced is an aqueous ammoniacal ionic solution of zinc acetate.
When applying an aqueous ammoniacal ionic solution of zinc acetate in-furrow to corn kernels in accordance with the present invention, the corn kernels are preferably placed in-furrow in 15xe2x80x3 to 40xe2x80x3 rows and the solution is preferably dispensed in-furrow at a rate of ⅓ pint to xc2xd pint per acre. When applying an aqueous ammoniacal ionic solution of zinc acetate in-furrow to soy bean seeds, the soy beans are placed in-furrow in 7xe2x80x3 to 40xe2x80x3 rows and the solution is dispensed in-furrow at a rate of ⅓ pint to xc2xd pint per acre. When applying an aqueous ammoniacal ionic solution of zinc acetate in-furrow to wheat seeds in accordance with the present invention, the wheat seeds are preferably placed in-furrow in 7xe2x80x3 to 10xe2x80x3 rows and the solution is preferably dispersed in-furrow at a rate of ⅓ pint to xc2xd pint per acre.
Employing the aforementioned methods results in stimulation of root growth to seedlings and post-emergent plants at the earliest developmental stages, increased plant growth in later stages, and increased crop yield, all without apparent injury to seeds or plants. The aforementioned methods have been employed under windy or wet weather conditions during which application of fertilizer by traditional pressure broadcast spray methods would typically be avoided.
A more complete appreciation of the present invention and its scope can be obtained from understanding the accompanying drawings, which are briefly summarized below, the following detailed description of presently preferred embodiments of the invention, and the appended claims.